Solar cells are photovoltaic components for direct generation of electrical current from sunlight. Due to the growing demand for clean sources of energy, the manufacture of solar cells has expanded dramatically in recent years and continues to expand. Various types of solar cells exist and continue to be developed. Solar cells include absorber layers that absorb the sunlight that is converted into electrical current. The absorber layer is the layer in which photons from sunlight become converted to electrical current. The ability of the solar cells to absorb sunlight and convert it to electrical energy is of critical importance. Thus, the quality and performance of the absorber layer are therefore of paramount importance. The composition of the absorber layer and the structure of the absorber layer are of critical importance in order to maximize the efficiency of electrical current production. The formation of the absorber layer and its placement on the solar cell substrate are therefore also critical operations.
Various types of absorber materials are used in various solar cells. Silicon is one particularly popular type of absorber material. Solar cell absorber materials formed of other materials, for example CIGS, copper indium gallium selenide, are also used. For a solar cell having a particular two-dimensional area, it would be most advantageous to absorb as much sunlight as possible. Solar cells have flat surfaces and include absorbing panels with flat surfaces. The sunlight absorbed by the solar cell is generally limited to sunlight that impinges upon the solar cell surface at an angle generally perpendicular to the panel surface. When the sunlight is at oblique angles to the panel surface, light is reflected and not absorbed. This results in poor efficiency in energy harvesting. In typical solar cells that have two dimensional, i.e. flat absorber layers, this light reflection results in a poor efficiency of converting all available photons to electrons and represents a loss in potential energy harvesting. During winter months or morning or evening hours when sunlight is not directly above and not orthogonal to the surface of the solar plate, the inefficiency in energy harvesting is particularly troublesome. In many cases, approximately thirty percent of incident sunlight is reflected off of the surface of the solar cells.
It would be desirable to produce and utilize an absorber layer that absorbs sunlight from various incident angles.